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Unsafe Rust is just Rust, but there's a few extra things you can do inside unsafe blocks that you can't normally do outside them (because they're unsafe). I wou

Unsafe Rust is just Rust, but there's a few extra things you can do inside unsafe blocks that you can't normally do outside them (because they're unsafe). I wouldn't call it a different language.

woodruffw 4y ago
See my response to 'kibwen. We can nitpick all day about whether it's really a separate language; I think it satisfies at least one important definition of "language" by having its own separate syntax and semantics that aren't accessible to Safe Rust.
- p1necone 4y ago
  But by that argument every feature in a language is it's own separate language. "This is the language that can only be written inside function definitions", "This is the language that can only be written inside ternary operators" and so on.
  - woodruffw 4y ago
    Sure: you can clearly drive this to absurdity. The list I gave was the ones I've heard people in the Rust community, including official Rust language documents, refer to as separate languages. Does that guarantee that we're carving the nature of "computer language" at its joints? No; it's merely a shorthand for expressing the range of syntaxes and semantics that you need to know to "fully" know Rust.
- rascul 4y ago
  What syntax is different with unsafe?
  - woodruffw 4y ago
    Unsafe Rust's syntax is a superset of Safe Rust, meaning that there is syntax in Unsafe Rust that will not compile in Safe Rust[1]. [1]: https://doc.rust-lang.org/book/ch19-01-unsafe-rust.html https://doc.rust-lang.org/book/ch19-01-unsafe-rust.html
    - biorach 4y ago
      It's the same syntax. There are no special operators in unsafe rust. All unsafe code is syntactically valid safe code. The reason it will not compile it because certain operations are not permitted, not because of syntax errors
    - Ygg2 4y ago
      That doc needs to be rewritten. By that logic, closure Rust is another subset, and Iterator, so are pub (crate) modifiers, etc. It just allows access to: raw pointers, unsafe fields and methods, and unsafe traits.

Unsafe Rust is just Rust, but there's a few extra things you can do inside unsafe blocks that you can't normally do outside them (because they're unsafe). I wouldn't call it a different language.

woodruffw 4y ago

See my response to 'kibwen. We can nitpick all day about whether it's really a separate language; I think it satisfies at least one important definition of "language" by having its own separate syntax and semantics that aren't accessible to Safe Rust.

p1necone 4y ago
But by that argument every feature in a language is it's own separate language. "This is the language that can only be written inside function definitions", "This is the language that can only be written inside ternary operators" and so on.
- woodruffw 4y ago
  Sure: you can clearly drive this to absurdity. The list I gave was the ones I've heard people in the Rust community, including official Rust language documents, refer to as separate languages. Does that guarantee that we're carving the nature of "computer language" at its joints? No; it's merely a shorthand for expressing the range of syntaxes and semantics that you need to know to "fully" know Rust.
rascul 4y ago
What syntax is different with unsafe?
- woodruffw 4y ago
  Unsafe Rust's syntax is a superset of Safe Rust, meaning that there is syntax in Unsafe Rust that will not compile in Safe Rust[1]. [1]: https://doc.rust-lang.org/book/ch19-01-unsafe-rust.html https://doc.rust-lang.org/book/ch19-01-unsafe-rust.html
  - biorach 4y ago
    It's the same syntax. There are no special operators in unsafe rust. All unsafe code is syntactically valid safe code. The reason it will not compile it because certain operations are not permitted, not because of syntax errors
  - Ygg2 4y ago
    That doc needs to be rewritten. By that logic, closure Rust is another subset, and Iterator, so are pub (crate) modifiers, etc. It just allows access to: raw pointers, unsafe fields and methods, and unsafe traits.